The present invention relates to seatbelt devices installed in vehicles such as automobiles, for restraining and protecting passengers in the event of an emergency such as vehicle collisions. In particular, the present invention relates to a seatbelt device wherein a pretensioner is provided to at least one of a lap anchor portion and a buckle portion.
Seatbelt devices may include a seatbelt retractor fixed to the body of the vehicle near the seat. The retractor spools the seatbelt in normal conditions in a manner whereby the seatbelt can be withdrawn. The retractor is also configured to prevent withdrawing of the seatbelt to allow the seatbelt to restrain and protect passengers in the event of an emergency such as a vehicle collision. The devices typically include a seatbelt which extends from the seatbelt retractor with the tip portion thereof being linked to a lap anchor portion fixed to the vehicle body at a portion on the outer side of the vehicle seat for example, so as to restrain the passenger belting the seatbelt. The devices also may include a buckle fixed to the vehicle body at a portion on the inner side of the vehicle seat for example, and a tongue slidably provided on the seatbelt so as to be detachably engaged with the buckle. Typically, the tongue engages with the buckle so that the seatbelt passes over the shoulder, chest, and waist of the passenger.
Normally, the seatbelt is relatively loosely wound by the seatbelt retractor and fit to the passenger to a degree wherein the seatbelt is woundable and withdrawable and does not give a feeling of pressure to the passenger, and in the event that great vehicle deceleration occurs in the event of an emergency such as the vehicle colliding, withdrawing of the seatbelt is prevented even though the passenger tries to move forward due to inertia, thereby restraining and protecting the passenger.
Certain conventional seatbelt devices may include a pretensioner for speedily restraining the passenger with a great restraining force by improving the restraining properties by removing the slack in the seatbelt and speedily tensioning the seatbelt in the event of an emergency such as the vehicle colliding. An example of such a seatbelt device is disclosed in Japanese Unexamined Patent Application Publication No. 6-344866 (incorporated by reference herein), wherein a pretensioner is provided to a lap anchor portion where the tip of the seatbelt is linked. With the seatbelt device disclosed in this Unexamined Patent Application Publication, the action of the pretensioner in an emergency such as mentioned above pulls the seatbelt linked to the lap anchor, thereby removing the slack from the seatbelt and speedily tensioning the seatbelt.
The pretensioner is fixed to the vehicle body for seatbelt devices having the pretensioner at the lap anchor portion. However, in order to facilitate assembly of the pretensioner to the vehicle body, the lap anchor portion and the connector portion of the pretensioner are separated. The lap anchor portion is normally inserted into and engaged with (latched to) the connector portion, thereby linking the seatbelt and the pretensioner.
However, in the event of pulling the seatbelt due to action of the pretensioner in the event of an emergency such as mentioned above, the inertial forces acting on the connector portion of the pretensioner in the direction of disengaging the latch mechanism latching the lap anchor and the pretensioner could conceivably lead to instability in the engagement between the lap anchor and the connector.
One of the many objects of the present invention is to provide a seatbelt device having stable engagement of the connector of the pretensioner and the seatbelt-side anchor even in the event that the aforementioned inertia force acts thereupon.